Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC 42-1: Differential Fluid Temperature Sensor (Short to Power)
- Before you troubleshoot, review the GENERAL TROUBLESHOOTING INFORMATION .
- When troubleshooting after the vehicle was driving, let the rear differential cool for more than one hour before doing this troubleshooting.
- Turn the ignition switch to ON (II).
- Make sure the HDS communicates with the vehicle and the SH-AWD control unit. If it doesn't, troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).
- Clear the DTC with the HDS.
- Check for DTCs with the HDS.
Is DTC 42-1 indicated?
YES - Go to step 5.
NO - Intermittent failure, the system is OK at this time.
- Turn the ignition switch to LOCK (0).
- Disconnect the rear differential fluid temperature sensor 2P connector and SH-AWD control unit connector A (20P).
- Check for continuity between rear differential fluid temperature sensor 2P connector terminals No. 1 and No. 2.Fig 1: Checking Continuity Between Rear Differential Fluid Temperature Sensor 2P Connector Terminals No. 1 And No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Repair short in the wire between rear differential fluid temperature sensor 2P connector terminals No. 1 and No. 2.
NO - Go to step 8.
- Connect the rear differential fluid temperature sensor 2P connector.
- Measure the differential housing temperature with an infrared temperature gauge near the mounting location of the rear differential fluid temperature sensor. The temperature should be below 176°F (80°C) before proceeding to the next step.
- Measure resistance between SH-AWD control unit connector terminals A8 and A18.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there 260 Ω or more?
YES - Update the SH-AWD control unit if it does not have the latest software (see UPDATING THE SH-AWD CONTROL UNIT ), or substitute a known-good SH-AWD control unit (see SH-AWD CONTROL UNIT REPLACEMENT ) and recheck. If the symptom/ indication goes away with the updated SH-AWD control unit, troubleshooting is complete. If the symptom/indication goes away with a known-good SH-AWD control unit, replace the original SH-AWD control unit (see SH-AWD CONTROL UNIT REPLACEMENT ).
NO - Replace the rear differential fluid temperature sensor (see REAR DIFFERENTIAL FLUID TEMPERATURE SENSOR REPLACEMENT ).
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.